1. Field of the Invention
The present invention relates to a camera, and more particularly to an improvement on a cartridge chamber lid lock device for setting the lid of a cartridge chamber of the camera to an unlocked state or to a locked state.
2. Description of Related Art
Cartridge chamber lid lock devices have been disclosed, for example, in Japanese Laid-Open Patent Application No. Hei 6-258699, Japanese Laid-Open Patent Application No. Hei 9-211596, etc.
The cartridge chamber lid lock device disclosed in Japanese Laid-Open Patent Application No. Hei 6-258699 is arranged to set a lock member at a locking position or at an unlocking position according to the movement of a constituent part of a photo-taking lens barrel. The cartridge chamber lid lock device disclosed in Japanese Laid-Open Patent Application No. Hei 9-211596 is arranged to set a lock member either at a locking position or at an unlocking position in association with the movement of a film sent out from a film cartridge.
However, in the case of the cartridge chamber lid lock device disclosed in Japanese Laid-Open Patent Application No. Hei 6-258699, since the cartridge chamber lid is locked or unlocked while the position of the photo-taking lens is at a part of a drawn-in region, the cartridge chamber lid is left in a locked state when the photo-taking lens barrel is at a drawn-out position with no film cartridge loaded. Under this condition, the camera cannot be loaded with a film cartridge. In loading the camera with a film cartridge, therefore, the photo-taking lens barrel must be once drawn into the drawn-in region. The cartridge chamber lid lock device thus makes a film cartridge loading operation troublesome.
Further, in the case of the cartridge chamber lid lock device disclosed in Japanese Laid-Open Patent Application No. Hei 9-211596, the cartridge chamber lid can be locked until a film sent out from a film cartridge is completely rewound. This arrangement allows the cartridge chamber lid to be opened even before the completion of setting a film-using-state indicator after the completion of rewinding the film. If the cartridge chamber lid is opened and the film cartridge is taken out from the cartridge chamber before the completion of setting the film-using-state indicator after the completion of rewinding the film, the film-using-state indicator cannot be set at a correct position, so that it becomes impossible to find out the using state of the film cartridge.
In accordance with an aspect of the invention, there is provided a cartridge chamber lid lock device of a camera capable of, when no film cartridge is loaded in a cartridge chamber, allowing a cartridge chamber lid to be opened for loading a film cartridge into the cartridge camber irrespective of a position where a lens barrel is located in an optical direction, and capable of surely preventing the cartridge chamber lid from being accidentally opened when a film is in a state of being sent out from a film cartridge loaded into the cartridge chamber, and surely preventing the cartridge chamber lid from being inadvertently opened during process of setting a using state of the film cartridge.
The above and other objects and features of the invention will become apparent from the following detailed description of a preferred embodiment thereof taken in connection with the accompanying drawings.